Illuminating means



n- 3, 1931. L.. v. FOSTER ILLUMINATING MEANS Filed June 18, 1928 Du E l W F V N 0 CL ll- INVENTOR Patented Jan. 1 3

' 00., F noo Es'rEER. NEWYORK,

A oom onaiion OF new 031; I

" ILLU MINATING ME A NS .Appue u nf i a June 18,

This invention relates to illuminating meansand more particularly it refers to illui'ninators which. are'used for providing uniform lluminat on of olnects Wlnchare un- 5 deli observation, ..such; as an opaque object on thestage of a microscope, for nstance.

In "illuminating objects of this sort it "is Q highly -desirable that the illumination be v Q uniformand even on all sides of the/object so that shadows mayibe eliminated; Various methods have been used for the purpose otproviding illuminationiof "the che ra"cter not satisfactory asonlyone'side of the. object is properly illuminated and objectionable.

shadows are produced. Another method inx' 'olves the use of a special, circular shaped; light source Which is adapted to illu'minate the object on allsides. v This isop'en to the objection that it causes an excessive amount a special design it is not convenient to obtain: v

' niiifor-m, "shadow free illumination "of the "LO. Some rays reach theobjecti Odi om. .t lle.lamp14 bilt tlieserays do not scribed and pointed out "in of heat, and further, this type of light source is also relativelyexpensive and sinceit is of new parts for replacement. a

One of the objects of the present invention is to provide a meansfor evenly illuminating aniobject of the character described.v Another object is to provide a relatively simple and inexpensive illuminating .means which Will uniformlyilluminate an object under H observation. Other objects and advantages;

reside in certain" novel featuresjof construc "tion, arrangement and combination of parts;

which ill'be hereinafter more fully de claims. Referring tothe drawings: f .Fig. 1 shows "a method of USHIgQIIG i'orm f Fig.2 shows atop of my illuminating device shown in Fig. 1.

Fig. 3-shows a s'ectionalview of a modification. f' r i Fig. 4 shoWsa top plan view of the device shoWn'inFig. 3. 7, y Similar reference; characters refer to the 1 can escent lamp 1 1 'yvh'i'chfj {cured m pnte 12,"may be n 11 on lring stand .1 8-, ;fo,r instanceyto hold the described. Inone: of these" methodspsthe v opaque object is illuminated by a directbeam the appended I .opaque objects- .or specimens;

i Figsi l a I have hawn ice being shown in verplan View of the form 'Fig fl, comprises ajsubstantially ovalyor pear-i'shaped shell "10 havingjanobservation lamplfsoeket 1.3 in which is-(mounted the-in- Su lyj' by Wire. .15. lf-rod 16, se-

pared, as by 1 a plying a vvhite'Tpaint or lacquer, for example; so as to reflect a uniformly difiiused light.

' In Fig;.;1 ,"I- have shown one form tray are reflectedto -the object other rays are differently reflected and the combined refconnectedto'a-p I 60 g f fed to clamp "illilriii'natinggdevice inanyfadjustedposition. I I fTheinner-surface.ofshell lQ is suitably preof'light whichis produced by a relatively" powerful sourceof light. This nethodfis flections' resultin the production of an" even,

v rb fythe even illumination'of the object. llhe uniformly; illuminated object ,O, can. be

opm rinstrumem as. shown in Fig.1, "for example. {The illumination produced .by my im r ved d i els h h isatisfactbry for. use in}taking}.photomicrographs of form offiny device wherein .ZO- indiCate'sfa shelltvhich comprises, substantially, a half section of {an ellipsoid: of 'revolution. An

observation opening 21 isprovided at'Ione end of the. shell anda tubularimember :22 is secured in theopeningfll. At the other I end. of theshell 20'zthereis'mountedlainp socket 23 which carrieslthe" incandescent lamp 24 fsuppliedwith'currilt ,by-wire 2 5;.

The lamp2t is mounted so as to be .posil s tioned approximatelyat one focus of the l 1 opening ll adjacentone end of said shell. A 'p1atef12, secured} to shell 10, carries ja ellipsoid and the observation opening 21 is substantially in line with the other'focus of the ellipsoid; Hence, when an object is placed below the opening 21 it will be positioned approximately at one focus of the ellipsoid and will, receive a maximum amount of reflected light since-light rays J satisfactorily for uniformly illuminating an 1 emanating from a light source at one focus of an ellipsoid of revolutionare reflected'to the other focus of the ellipsoid.- The inner surface of shell 20 is also suitably prepared, as by applying a flat white paint or lacquer,

for example, so as to reflect and diffuse the 7 light rays. Light rays from lamp 24L will be reflected by the inner surface ofshell 20 and will produce uniform illumination on an'object' placed under the observation opening 21. A clamping device 26 is secured to the tubular member 22 and provides a means whereby the illuminator may be adjust'ably secured to a microscope, i I

The form of my device shown in Figs. 1 and 2 approximates,substantially, that ofia section of'an ellipsoid of revolution. Either 7 type of my illuminating device functions 3. An illuminator for the field of an opticalinstrument comprising a shell having an opening at one side for the object to be illuminated, andopposite thereto an observation opening adapted to be alined' with the axis of said instrument,'and a source of light mounted within said shell at one side of said. observation opening in such position that light from said light sourcemay. fall upomthe interior surface of said shell at one side of said observation opening.

' LEON v. rosrnn.

opaque object or specimen requiring direct V illumination on'the stage of-a microscope.

My improved =device i's especially satisfactory forilluminatingspecimens on the stage of'a relatively low power binocular microf:

scope. Although I have illustrated my device in use with a *microscope, it can obviously be used to uniformly illuminate any object which is under fdirect observation without the aid of a microscope B h types of my improved device are relatively simple and inexpensive,yet eflicientinoper ation. My device utilizes a' well known type of incandescent lamp which can be readily obtained on the] market," thereh avoiding the necessity of ordering a specla sh'aped'lamp. a v 7 Fromthe foregoing it is '7 ap arentthat I'am able to attain the objects 0 'myinventi'on and provide an eificient'," yet inexpensive and simple, means forruniformly illuminating an object under observation.

I claim:

p 1. An illuminator for the field of an optical instrument. comprising a shell having an. observation opening adjacent one end thereof, and a'source of light mounted therein and at theother end of said shell,

said shell having substantially the cont'our' of a half section of an ovoid.

2. An illuminator of the class described comprising a' member having substantially the contour of a half section of an ellipsoid having'one side open for receiving a specimen and having an'observation open ng therein which *i's'approximately in line with onefocus of the ellipsoid and alightsource positioned substantially at the other ,focus I ofjthe ellipsoid.

rthe oprposite side of said shell from said light source and be reflected therefrom to 

